Luna

Luna was a talking cat and advisor to Usagi Tsukino. It was she who first detected Usagi's power, but at the time did not realize that she was the Moon Princess. Luna and her partner Artemis were advisors to Queen Serenity in the Silver Millennium, and when the kingdom was ruined Serenity used the power of her Silver Crystal to send the two cats to Earth's future in order to awaken the Sailor Senshi.

She and Artemis one day married and had a daughter named Diana who became the advisor to Chibiusa. Chibiusa's toy Luna P was also modelled on Luna.

(Source: Wikimoon)